This group of functions allows you to apply image processing and special effects functions on an arbitrary region of interest (ROI). You can specify a shape, such as ellipse, polygon, or freehand, or a 1-bit mask for identifying which pixels to include/exclude from image processing algorithms.

To apply an image processing function on a non-rectangular ROI, create the ROI using IG_IP_NR_ROI_to_HIGEAR_mask(), or use a 1-bit image, and associate it with the HIGEAR handle on which you are going to apply the processing function, using IG_IP_NR_ROI_mask_associate(). Consequent calls to image processing functions on this image will only affect the area specified by the ROI.

IG_IP_NR_ROI_control_get()	Returns the current ROI control settings.
IG_IP_NR_ROI_control_set()	Detects an area of pixels using a specified threshold.
IG_IP_NR_ROI_mask_associate()	Associates a mask HIGEAR, as specified by the AT_NR_ROI_MASK structure, with the image referenced by hIGear.
IG_IP_NR_ROI_mask_delete()	Deletes the mask HIGEAR created by IG_IP_NR_ROI_to_HIGEAR_mask().
IG_IP_NR_ROI_mask_dilate()	Dilates ROI mask by the specified number of pixels.
IG_IP_NR_ROI_mask_erode()	Erodes ROI mask by the specified number of pixels.
IG_IP_NR_ROI_mask_unassociate()	Removes the non-rectangular ROI information from a HIGEAR image, but does not delete the mask HIGEAR.
IG_IP_NR_ROI_to_HIGEAR_mask()	Builds a non-rectangular ROI mask from a set of segment descriptors that you pass in.